A battalion of Sudanese troops arrived in Yemen’s southern port city of Aden on Saturday, military officials said, bolstering Saudi-led Arab forces trying to keep out the Iran-backed Huthis and curb the growing presence of Islamist militants.

Aden, a strategic port and shipping hub, became the seat of the Yemeni government earlier this year after the Huthis, a clan from northern Yemen which follows the Zaydi branch of Shiite Islam, seized the capital Sanaa and forced President Abd-Rabbu Mansour Hadi to flee to the south.

A military source in Aden said that 300 Sudanese soldiers and officers arrived by sea on Saturday. Their purpose was to “help maintain security for the city against the Huthis and Saleh,” the source said, referring to former President Ali Abdullah Saleh, whose supporters have sided with the Huthis.

Hadi escaped to Saudi Arabia as the Huthis advanced towards Aden in March and has since been back only for a brief visit.

But Prime Minister Khaled Bahah returned after anti-Huthi fighters, backed by the Arab coalition, drove the Huthis and their allies out of the city in July.

However, they have not managed to restore security there.

Islamist militant suicide bombers killed 15 people in attacks on the Yemeni government’s headquarters and Arab coalition outposts in Aden on October 6.

“Our troops in Yemen are ready to do their military task under the command of the alliance military leadership,” Sudanese army spokesman Brigadier General Ahmed Khalifa Alshami said.

“Sudan is committed to restore legitimacy in Yemen.” The Arab coalition says its aim is to restore Hadi’s government to power in Yemen. At least 5,400 people have died since it began an air offensive in March.

The Arab coalition spokesman, Brigadier General Ahmed al-Assiri confirmed the arrival of the Sudanese troops to Arab television channels.

They will join contingents from the United Arab Emirates, Saudi Arabia and Bahrain on the ground.

Hadi supporters, backed by Arab forces, recently made some gains in the strategic Bab al-Mandab strait and in Marib, a province east of Sanaa and home to much of Yemen’s oil wealth.

But the Huthis remain in control of much of the country, despite almost daily air strikes.

Unidentified gunmen killed a UAE national in Aden on Saturday at a shop, according to a local security source. The UAE state news agency WAM reported that a coalition soldier had died but gave no further details.